Posted
by
Soulskill
on Monday March 21, 2011 @05:03PM
from the free-range-sunlight dept.

An anonymous reader writes "The tallest building in the United States is set to become a soaring vertical solar farm, as Pythagoras Solar just launched a project to emblazon the building's glass façade with transparent photovoltaic panels. The new windows, dubbed high power density photovoltaic glass units, are a clever hybrid technology that lays a typical monocrystalline silicon solar cell horizontally between two layers of glass to form an individual tile. An internal plastic reflective prism directs angled sunlight onto the solar cells but allows diffuse daylight and horizontal light through. The high-profile project will begin on the south side of the 56th floor and could grow up to 2 MW in size — which is comparable to a 10-acre field of solar panels."

Actually you can thank the buildings designers for that. most skyscrapers suffer from updrafts, that could be strong enough to lift 120 pounds. Think about it, that cute secretary in those awesome heels, walks by the open window and gets sucked out of it because the wind shifts just right. It has happened.

But people tend to notice very windy days. They don't keep a running count of the average wind speed

We have a similar situation in New Zealand. Wellington is known as the windy city, but it has a lower average wind speed than Auckland. Wellington has more windy days than Auckland, but it also has more no-wind days, which brings the average down.

This is because Auckland gets sea-breezes more often than not during the summer, while Wellington doesn't, but Wellington gets pummelled by gradient breezes due to i

I wish the 108th story of the Sears Tower did have windows that could open, so you would be able to compare it to the 108th story of a skyscraper in New York... oh wait, nevermind, there isn't one;)

Anyway, I think in general (and these comments in particular) people are more interested in the gusts and max wind speed. The ave max wind speed in Chicago is about 58 MPH, and only 40 MPH in New York (Manhatten). Not even close!

If you updrafts that are that powerful you can use *them* to generate power. Then run fans to swap air from the outside to the inside. Fairly simple. Bonus would be to filter it first.

You can even design it passively. Have intakes on the outside and exhaust ports on the top the building. Use them to suck the air out from the insides of each of the floors. All you would need is a central line through the whole building vertically where the negative pressure causes the fresh air to be su

There was once a story about a guy named Shorty that came up with the idea that you could build a tube that would extend from near to the ground to, oh, say 30,000 feet. The idea was that all the pollution and particulates would be sucked up that stack into the lower pressure very high up, thus virtually eliminating the sort of inversion layer pollution that exists in bowls like Los Angeles, Phoenix and Denver.

The gizmo was called (in the story) a "shortstack". As opposed to a smoke stack.

Come to Hong Kong. The days of the skyscraper are far from over here - we don't have earthquakes, and we have no more land available - the population density here is 6480 people per square kilometre over the whole territory, but most of Hong Kong's land is unusable, so the real density in urban spaces is much higher. The official factsheet suggests 53 110 pp/sq.km, but wikipedia goes for 130 000 pp/sq.km in Mongkok, the busiest area.

Actually you can thank the buildings designers for that. most skyscrapers suffer from updrafts, that could be strong enough to lift 120 pounds. Think about it, that cute secretary in those awesome heels, walks by the open window and gets sucked out of it because the wind shifts just right. It has happened.

When you consider the inefficiencies of powering it through the grid, going through miles and miles of resistance on the wire, you're going to offset much more than 2MW. Bringing the energy source onsite is a smart move.

According to an article about projects started in '09 to reduce it's usage 80% reduction in power is 52 million kWh annually, putting its total usage at 65 million kWh annually.

this gets me at 2000 ish days of pure sunlight (at 2MW, when I say pure, I mean 24 hours of it) to completely meet its annual demands (divide all numbers by 365 to get your daily number).

The articles I've seen have said 68GWh was the reduction, putting its total pre-upgrades usage at 85GWh. That means it averaged about 10MW of usage at any given time. Also, don't forget the other upgrades they're planning/implementing to bring energy costs down: wind turbines and solar water heaters, efficiency upgrades like replacing single pane windows and outdated elevators, and installing advanced lighting systems and more efficient plumbing.

The building is now and forever will be called the Sears Tower. No locals call it the Willis Tower. No non-locals should either. It's a landmark and a piece of architectural history. Like the headline says, it is "Chicago's." In this sense, it will always belong to the public, and the ability of some random foreign insurance firm to finagle some temporary naming rights will never change that.

Naming rights on a building after it's completed is completely stupid. One of our local buildings has been renamed several times, and you find people referring to it by all of those names, even though the most recent naming is back to what it was originally and was nearly a decade ago.

Personally, I refuse to call it anything other than the Sears Tower, just because I think it's asinine to rename a world renowned landmark.

And this is what's annoying. Reputable news sources will feel an obligation to use the official name, while at the same time likely realizing that no one wants to call it that. Ends up being divisive. It'd be nice if more news sources would take a stand and just use the old name. It'd be a nice way to express how futile it really is to sell naming rights to an iconic structure or location.

Funny, the native Athabaskans felt the same way when white men named it McKinley despite the fact that it was called Denali before conquering invaders ever saw it. But I suppose that you feel the winners get to make the names, eh? In that case, I guess the Athabaskans must have won, because it's called Denali now.

This is nothing at all like a major landmark being renamed by a megacorporation. In fact, renaming Denali to McKinley is akin to renaming the Sears Tower to Willis Tower. Changing McKinley back to

This is nothing at all like a major landmark being renamed by a megacorporation. In fact, renaming Denali to McKinley is akin to renaming the Sears Tower to Willis Tower. Changing McKinley back to Denali would be like changing Willis Tower back to Sears Tower.

Heh. I'm having a vision of 40 years in the future of someone complaining that the iconic Willis Tower of Chicago is having it's name bastardized and changed to Sears of all things. The nerve!

By definition, nerds pedantically correct people's statements for the sake of accuracy (of minutiae, or to show off knowledge). Being different is a side effect of other people generally not caring about correctness in detail.:)

That power is already used. So, unless this blocks enough light that people have to start turning on lights because of it, it's a gain. Which is to say it'll reduce the amount of electricity that the building uses.

Only if the net output of the solar cells over their projected lifetime exceeds the energy costs to manufacture them and affix them to the side of the building. This is a publicity stunt, when in fact revamping the environmental controls could potentially yield greater energy savings at lower cost. Just because something can be done doesn't mean it should be -- a good engineer looks for the most efficient means of accomplishing the objective. Slapping solar cells on the roof of a Prius technically makes it go farther on a gallon of gas, but the difference is so trivial that it doesn't justify the cost of the solar cells.

If you want to have a tall building that consumes electricity, you can't say "produce it elsewhere"

which I personally find precious. We should be putting solar power in by default, and using other sources if solar fails, period. Because all of the other sources are stored solar power that's been converted, using the original source makes more sense.

Once we have one building doing this, we can have others.

We can also stop the nonsense about putting most of the solar power in deserts. We need to start to have urban power generation that doesn't generate smoke pollutants. Solar is

We should be putting solar power in by default, and using other sources if solar fails, period.

Sure, but why stop there? Obviously it would make WAY more sense to have them grow their own food, too. Two floors out of every three should be farms! And, of course, they should process their own sewage by default. And weave their own curtains. And there should be a factory level for making TV's and computers. And maybe a forest and a pulp-mill on the roof, to create all those TPS reports from scratch.

Yep, trade is for fools - a REAL building should be completely self contained!

That's cute, but, in reality, Hong Kong is one of the worlds largest trade centers, and THE largest re-exporter on the planet. The value of imports and exports is larger than the nations GDP. It's a free-market traders wet dream, and the antithesis of a self-sustaining community.

We should be putting solar power in by default, and using other sources if solar fails, period.

Sure, but why stop there? Obviously it would make WAY more sense to have them grow their own food, too. Two floors out of every three should be farms! And, of course, they should process their own sewage by default.....

Actually that wouldn't be a bad thing - when the building is the size of a small town or city one could certainly have a number of specialists doing all of those things. I think slashdot had an article about farms in scyscrapers a while ago but I can't be bothered to find it.

You haven't kept up to date on the dropping price of solar, and the rising price of anything non-renewable. Solar is a much more economical prospect nowadays. Have you been asleep for the past ten years?

Only if the net output of the solar cells over their projected lifetime exceeds the energy costs to manufacture them and affix them to the side of the building.

Which, since they are conducting an extensive remodel [earth911.com] of the building to improve energy efficiency including replacing the single-pane windows anyway, they most likely will, that makes it a good decision.

Just because something can be done doesn't mean it should be -- a good engineer looks for the most efficient means of accomplishing the objective.

Exactly, and that often means making use of multiple techniques in concert, including some smaller optimizations that nevertheless contribute to the overall objective, and ideally take advantage of changes you're already making. For example, you might see that one of the biggest improvements you can make to the building is to replace all the old poorly insulated windows with new efficient ones. And then you can look at whether or not in-window solar would be worth it in the context of having already decided to replace all the windows.

In the case of a building which requires windows I would suggest only counting the solar cell manufacturing cost as the glass and installation cost happen regardless. Unless said building didn't require the windows to be replaced, in which case it's valid to count it.

Making the building more energy efficient and adding the solar cells are not mutually exclusive. Why can't other energy efficiency be implemented in addition to adding the solar cells? The article doesn't mention anything else that's been done for efficiency, but that doesn't mean that a lot hasn't been done or isn't in the works. In addition to generating electricity these cells will also lower cooling costs. It would have been nice if they could have provided an estimate of how much power will be saved

If you read the article (yeah I know it's Slashdot) you would find out that these new windows also lower the solar gain reducing the need for cooling in the summer. So the building becomes more efficient in multiple ways.

I can imagine that your earlier suggestion of being able to open windows would probably be impractical (possible dangerous) to retrofit onto a skyscraper that was not designed to support them (although I am a big fan of using ventilation instead of air conditioning). So what should they have done first, and how do you know that they haven't done it already.

I was just about to hit submit when I came across a post by AvitarX [slashdot.org] that addresses this. It seems this is just he latest in a series of improvements mad

It used to be the Sears Tower until Willis (Todd Bridges) from Diff'rent Strokes died in a shootout in the lobby.... One of the Chicago mob mayors, Daily, I think then forcibly re-named the building against the owner's wishes and closed the municpal airport because another Willis, this time Bruce Willis was threatening to come in and blow up shit at THAT airport for another movie.

Given how far north Chicago is, and the kinds of winters they get, I'm curious to know if it will be worth the effort. And it it will deliver on the energy claims. I'm curious to know what kind of power they'll get from that amount of surface area compared to the same installation somewhere in the southwest.

In some senses, it doesn't matter. Pilot projects (assuming this is a pilot project--I don't know of any other place that's tried anything like this) ALWAYS cost more per unit scale. The goal is to gauge its efficacy. If it works well, then see how/whether it can be improved upon and implement it again. Vertical solar farms would be an interesting solution to the acreage issue.

Seems like it would be a lot more efficient to put these on a high rise in Phoenix, with an average of 6.58 hours per day of sunlight. Then again, I'm not a marketing guy for Big WIlly, or "journalist" at inhabitat, so what do I know...

Sure it'd be more efficient to put them on high rises in Phoenix. Sadly, though, the Sears Tower would still be in Chicago, consuming all that energy. The solar panels are just one part of the retrofit designed to reduce the building's external power consumption. And regardless of how much better solar panels perform in Arizona instead of Chicago, as long as they produce enough power to pay for themselves before they need replacing, then it's a good idea.

Please show me where in the article it says these panels will "produce enough power to pay for themselves before they need replacing." I think the likely hood of that scenario is much greater somewhere with twice as much sunlight.

I agree that this is part of a larger push to reduce the buildings power consumption, which is great for marketing to eco-consious tenants (pretty much everyone nowadays). However, I doubt the viability when something is this short on details. But hey, what are a couple thousand

The 29 minute video does contain some statistics (for instance, NYC spent $33 million a year on it's recycling program). But I doubt you watched it since your first reply came 17 minutes after I posted the link.

Penn and Teller are fun to watch, but they admit their show is for entertainment not education.

Citation, please. I've watched plenty of their shows, and the spirit is clearly to uncover, well, bullshit. Of course they try to do it in an entertaining manner, but that doesn't mean they don't believe in what they are doing.

I don't know that they will, but that's the criterion for judging if it makes sense to do it. Obviously it would be more likely with twice as much sun, but that doesn't mean it isn't net-positive here.

As they're already doing like 50 "green" things to the tower, it wouldn't make sense to just throw this one on the pile for a trivial shift in perception, if it wasn't worth it economically.

So, like I said, I don't know that it is worth it, but it is not impossible, and I'm certainly not going to take the lac

Yeah, but that's a yearly average. It uses a LOT more electricity for A/C in the summer, when the sunlight averages are much higher.

In any case, I don't think anyone believes this is going to be a particularly cost effective project energy-wise (the installation and maintenance costs to install that many transparent solar panels 800 feet off the ground must be huge). But it is a huge marketing maneuver to make the tallest building in the United States run largely on its own solar power; kind of don't thin

It sounds to me like they are trying to capture all of the direct sunlight but none of the ambient (ie diffuse and horizontal) light. Think of it this way, you can put an awning on a window and still see everything outside even though it completely blocks direct sunlight (during parts of the day). I wonder what the sun looks like through these windows.